Technical Field
[0001] The present invention relates to an inkjet processing solution. The present invention
further relates to an ink set and a textile printing method using the ink set.
Background Art
[0002] It is known that, in the inkjet recording method, a preprocessing solution is applied
prior to application of ink. For example, a method using a processing solution containing
fine particles as components forming a color material and an aggregated matter in
ink has been reported.
[0003] Patent Literature 1 discloses an inkjet recording method in which a colorless fluid
containing fine silica particles is applied to a targeted recording material, and
then a non-aqueous recording fluid containing oil black is applied. Patent Literature
2 discloses use of a solution containing fine particles or fine particles and a binder
polymer as a processing solution.
[0004] The fluid containing such fine particles contains reactive fine particles, so that
a reaction constituent can be added to the fluid by a large amount. Meanwhile, a fluid
composition containing reactive fine particles contains corrosive ions at a high concentration.
This is because corrosive ions are inevitably contained during production of the component
of the fluid composition, and corrosive ions such as chlorine ions and acids are added
as sub ions to secure dispersion stability of a component reactive with the color
material. For this reason, simply using the fluid composition as a raw material of
a processing solution causes, in many cases, a problem due to fluid-contact of the
corrosive ions, which problem may corrode a metal-based material of a head that discharges
the processing solution.
[0005] Regarding this problem due to the fluid-contact of corrosive ions, there has been
reported that the fluid-contact is improved by specifying the chlorine ion concentration
in a processing solution containing a cationic polymer to 3000 ppm or less (Patent
Literature 3). In addition, there has also been reported a method for producing processing
solution in which corrosive ions (halogen ions) are replaced with less corrosive ions
by an ion exchange method in which ions are replaced during production of a processing
solution containing one or more kinds of components reactive with a color material
(Patent Literature 4).
Citation List
Patent Literature
Summary of Invention
[0007] An inkjet processing solution according to an aspect of the present disclosure contains
a cationic polymer and lactic acid. In addition, the halogen ion concentration is
5 g/L or less and the pH is 7 to 9.5.
Brief Description of Drawing
[0008] FIG. 1 is an example of inkjet recording performed using an inkjet processing solution
of the present embodiment.
Description of Embodiments
[0009] According to the description in Patent Literature 3 as described above, a cationic
polymer, a cationic surfactant, or the like is used as the cationic substance constituting
a fluid composition, and the cationic substance contains a little amount of chlorine
ions such as hydrochloric acid roots resulting from an acid treatment or the like
performed in synthesis and purification of the cationic substance (paragraph 0008).
Thus, it is considered that when the chlorine concentration is 3000 ppm or less, the
added amount of the cationic polymer as a reaction constituent with a color material
cannot be increased, and the effect of aggregating with the color material cannot
be sufficiently obtained.
[0010] In addition, it was found that removing halogen ions by an ion exchange method as
in the technique disclosed in Patent Literature 4 makes a cationic polymer unstable
to heat, which disadvantageously causes yellowing by heat at a place where the processing
solution is applied.
[0011] Meanwhile, all of Patent Literatures 1 to 4 described above are about inkjet processing
solutions for printing on a paper medium such as a plain paper, and are not assuming
textile printing on cloth or the like. In a case of inkjet recording used for textile
printing, a processing solution containing a binder resin is usually used for pretreatment.
The binder resin penetrating into gaps between fibers causes binding of fibers to
each other and disadvantageously makes the fabric stiff and degrades the texture,
such as touch, of the fabric. These disadvantages are peculiar to textile printing.
[0012] Hereinafter, embodiments according to the present invention will be specifically
described, but the present invention is not limited to the embodiments.
[Inkjet processing solution]
[0013] An inkjet processing solution (hereinafter, also simply referred to as a "processing
solution") according to one embodiment of the present invention contains a cationic
polymer and lactic acid, has a halogen ion concentration of 5 g/L or less, and a pH
of 7 to 9.5.
[0014] The processing solution of the present embodiment is a preprocessing solution applied
to a recording target prior to application of ink. The cationic polymer contained
in the processing solution reacts with and aggregates with the pigment contained in
the ink, which is subsequently applied, to secure excellent chromogenic property.
[0015] The processing solution of the present embodiment has a low halogen ion concentration,
so that corrosion of an inkjet head member due to halogen ions can be suppressed.
In addition, since the processing solution includes lactic acid and has a pH in the
range described above, yellowing of the cationic polymer having a low halogen concentration
can be reduced.
[0016] That is, according to the inkjet processing solution of the present embodiment, corrosion
of an inkjet head member and yellowing of a recording medium can be suppressed in
inkjet recording, and excellent chromogenic property (image density) can be obtained.
Furthermore, for textile printing, use of the inkjet processing solution of the present
embodiment is advantageous in improving the texture of fabric.
[0017] The cationic polymer contained in the inkjet processing solution of the present embodiment
is not particularly limited as long as the cationic polymer is positively charged.
For example, the cationic polymer may be ammonium-containing polymers, amine-containing
polymers, polyallylamine, polyvinylamine, polyimine, polyvinylpyrrolidone, polyethyleneimine,
polyvinylpyridine, aminoacetalized polyvinyl alcohol, ionene polymer, polyvinylimidazole,
polyvinylbenzylphosphonium, polyalkylallylammonium, polyamidine, and polyaminesulfone.
Among these, from the viewpoint of obtaining further excellent chromogenic property,
preferable examples in particular are a quaternary ammonium-containing polymer, diallyldimethylammonium
sulfur dioxide copolymer, diallyldimethylammonium chloride acrylamide copolymer, diallyldimethylammonium
chloride polymer, dimethylamine-ammonia-epichlorohydrin polycondensate, and dimethylamine-ammonia-epichlorohydrin
polycondensate. These can be used solely or in combination of two or more kinds.
[0018] The weight-average molecular weight of the cationic polymer used in the present embodiment
is not particularly limited, and is preferably about 1000 to 10000. The molecular
weight in this range is considered to improve the performance of discharging from
the inkjet head.
[0019] The content of the cationic polymer is preferably 0.3 weight % or more and 35 weight
% or less with respect to the entire processing solution. The content of the cationic
polymer in this range is considered to further improve chromogenic property (image
density) and further suppress yellowing of a recording medium. A further preferable
lower limit value of the content of the cationic polymer is 0.5 weight % or more,
further preferably 1 weight % or more. Further preferably, the upper limit value is
29.5 weight % or less, still further preferably 20 weight % or less.
[0020] The processing solution of the present embodiment further contains lactic acid, and
the lactic acid may be contained in a form of lactic acid ions.
[0021] The content of the lactic acid is preferably 20 weight % or less with respect to
the entire processing solution. It is considered that the content of the lactic acid
being in this range further improves chromogenic property (image density) and can
further suppress yellowing of the recording medium. A further preferable upper limit
value of the content of the cationic polymer is 17.5 weight % or less, more preferably
15 weight % or less.
[0022] The lower limit value of the lactic acid content is not particularly limited, and
is preferably 0.2 weight % or more, further preferably 0.3 weight % or more, from
the viewpoint of obtaining the effect of stabilizing the cationic polymer.
[0023] In the processing solution of the present embodiment, the remainder other than the
components described above is usually water or an aqueous solvent composed of water
and organic solvent.
[0024] Examples of the organic solvent that can be contained in the processing solution
include glycol, alcohol, aliphatic hydrocarbon, aromatic hydrocarbon, ketone, ester,
ether, and vegetable oil. Examples of the water-soluble organic solvent include polyhydric
alcohol, ether compounds of polyhydric alcohol, nitrogen-containing compounds, alcohol
compounds, sulfur-containing compounds, propylene carbonate, and ethylene carbonate.
[0025] Examples of the polyhydric alcohol include first diol compounds having 5 or more
and 8 or less carbon atoms, second diol compounds having 2 or more and 4 or less carbon
atoms, 1,2,6-hexanetriol, glycerin, trimethylolpropane, sugar alcohol (for example,
xylitol), and saccharide (for example, xylose, glucose, and galactose).
[0026] Examples of the first diol compound include 2-methylpentane-2, 4-diol, triethylene
glycol, tetraethylene glycol, 1,5-pentanediol, and 1,2-hexanediol.
[0027] Examples of the second diol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol,
butylene glycol, and diethylene glycol.
[0028] Examples of the ether compound of polyhydric alcohol include ethylene glycol monomethyl
ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene
glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl
ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and ethylene
oxide adducts of diglycerin.
[0029] Examples of the nitrogen-containing compound include pyrrolidone, N-methyl-2 pyrrolidone,
cyclohexylpyrrolidone, and triethanolamine.
[0030] Examples of the alcohol compound include ethanol, isopropyl alcohol, butyl alcohol,
and benzyl alcohol.
[0031] Examples of the sulfur-containing compound include thiodiethanol, thiodiglycerol,
sulfolane, and dimethyl sulfoxide.
[0032] Among the organic solvents described above, glycols such as propylene glycol are
preferably used. These can be used solely or in combination of two or more kinds.
[0033] When the processing solution contains an organic solvent, the content of the organic
solvent is preferably 3 weight % or more and 50 weight % or less with respect to the
entire processing solution. The organic solvent contained in this range is advantageous
in that a processing solution having a viscosity allowing stable discharge can be
provided and drying of the processing solution can be relieved.
[0034] Furthermore, the processing solution of the present embodiment may contain a surfactant
to adjust the surface tension of the processing solution to an appropriate level.
The surfactant that can be used is not particularly limited, and examples of the surfactant
include nonionic surfactants, cationic surfactants, and anionic surfactants.
[0035] When the processing solution contains a surfactant, the content of the surfactant
is preferably 0.1 weight % or more and 5 weight % or less with respect to the entire
processing solution. Containing the surfactant in this range is advantageous in that
the processing solution having a surface tension allowing stable discharge can be
provided.
[0036] The processing solution of the present embodiment may contain other additives as
long as the effect of the present embodiment is not deteriorated. Examples of the
additive include dissolution stabilizers, desiccation inhibitors, antioxidants, viscosity
modifiers, pH adjusters, and antifungal agents.
[0037] The processing solution of the present embodiment, as described above, has a halogen
ion concentration of 5 g/L or less and a pH of 7 to 9.5. The halogen ion concentration
can be adjusted by obtaining a cationic polymer having a halogen ion concentration
adjusted using an ion exchange resin as described later.
[0038] The pH of the processing solution can be adjusted, for example, by adjusting the
added amount of lactic acid.
[0039] The halogen ion concentration of the processing solution is more preferably 3 g/L
or less. A more preferable pH range of the processing solution is 7 to 9.
[Method for producing processing solution]
[0040] The method for producing the processing solution of the present embodiment is not
particularly limited. An example will be described below. First, a column is filled
with a basic ion exchange resin and a cationic polymer is passed through the column
to obtain an adjusted cationic polymer having a reduced halogen ion concentration.
[0041] The obtained adjusted cationic polymer, lactic acid, an aqueous solvent, and components
to be added as necessary (for example, a surfactant) are mixed, whereby the processing
solution of the present embodiment can be obtained.
[Inkjet recording method using processing solution]
[0042] Next, a method of using the processing solution of the present embodiment and the
like will be described. The processing solution of the present embodiment can be used
as a preprocessing solution for an inkjet recording device 10, for example, as illustrated
in FIG. 1.
[0043] Specifically, the inkjet recording device 10 illustrated in FIG. 1 may include a
processing head 1 and a recording head 2, and the recording head 2 may include a first
recording head 2a, a second recording head 2b, a third recording head 2c, and a fourth
recording head 2d.
[0044] The processing head 1 discharges the processing solution to at least an image forming
region of a recording target P. The processing solution used here is the processing
solution described above. The processing head 1 is not particularly limited. Examples
include a piezo head and a thermal inkjet head.
[0045] The recording head 2 ejects ink to the image forming region of the recording target
P. The first recording head 2a, the second recording head 2b, the third recording
head 2c, and the fourth recording head 2d included in the recording head 2 respectively
discharge inks of different colors (for example, yellow ink, magenta ink, cyan ink,
and black ink). The number of recording heads is not limited to 4, and the number
of recording heads may be 1 to 3 or 5 or more. The recording head 2 is not particularly
limited. Examples include a piezo head and a thermal inkjet head.
[0046] The recording target P is placed on a mounting table 3. The processing head 1 and
the recording head 2 are disposed above the mounting table 3 so that the processing
solution and the ink can be discharged to the recording target P. Driven by a motor
(not illustrated), the mounting table 3 horizontally moves in a direction from the
processing head 1 toward the recording head 2 (for example, the leftward direction
in FIG. 1). The horizontal movement of the mounting table 3 conveys the recording
target P on the mounting table 3.
[0047] In the present embodiment, the recording target P is not particularly limited, and
may be a medium such as a plain paper, though the processing solution of the present
embodiment can exhibit a further effect when used in an application for textile printing.
Thus, the recording target P is preferably a medium that may be a textile printing
target.
[0048] In the inkjet recording, first, the mounting table 3 on which the recording target
P is placed moves horizontally to convey the recording target P to a position where
the recording target P faces the processing head 1. The processing solution is discharged
from the processing head 1 to the recording target P. The processing head 1 may discharge
the processing solution only to an image forming region of the recording target P,
may discharge the processing solution to a region wider than the image forming region
of the recording target P, or may discharge the processing solution to the entire
surface of the recording target P. It is preferable that the processing head 1 discharges
the processing solution only to the image forming region of the recording target P
so as to reduce the used amount of the processing solution to suppress degrading of
the texture of a textile printing article.
[0049] After the processing solution is discharged from the processing head 1, the mounting
table 3 on which the recording target P is placed further horizontally moves to convey
the recording target P to the position where the recording target P faces the recording
head 2. Then, the recording head 2 ejects ink to the image forming region of the recording
target P. In this manner, an image is formed by the ink in the image forming region
of the recording target P.
[0050] Although not illustrated, it may be configured that, after the ink is discharged
by the recording head 2, the mounting table 3 on which the recording target P is placed
further horizontally moves and a post-processing solution is discharged from another
processing head. The post-processing solution is a processing solution having non-chromogenic
property and does not develop color even when applied to the recording target P, and
is a processing solution that exhibits a function of enhancing fixability and ruggedness
(resistance to rubbing and scraping) of an ink image printed on the recording target
P by the recording head 2. As such a post-processing solution, a silicone-based processing
solution can be used. In this manner, a processed film is formed by the post-processing
solution on the image formed in the image forming region of the recording target P.
[0051] After discharging of the post-processing solution, the mounting table 3 on which
the recording target P is placed further horizontally moves to convey the recording
target P to a position where the recording target P faces a heating unit (not illustrated),
and the heating unit heats the recording target P to dry the ink and the processing
solution. The heating temperature is, for example, 120°C or more and 180°C or less.
The heating time is, for example, 1 minute or more and 10 minutes or less. By heating,
volatile components contained in the ink and the processing solution are dried, which
facilitates fixation of the ink and the processing solution to the recording target
P. As a result, the ink forms an image, and at the same time, the recording target
P processed by the processing solution is formed.
[0052] Note that, the way of using the processing solution of the present embodiment is
not limited to that for the inkjet recording device 10. The way of using the processing
solution can be changed, for example, as described in the following exemplary modifications.
For example, the inkjet recording device 10 may include a spray for spraying the processing
solution instead of the processing head 1 that discharges the processing solution.
Alternatively, the processing using the processing solution may be performed by immersing
the recording target P in the processing solution stored in a tank. Furthermore, in
the inkjet recording device 10, the mounting table 3 moves horizontally, but the processing
head 1 and the recording head 2 may move horizontally with the mounting table 3 fixed.
Alternatively, simultaneously with the mounting table 3 moving horizontally or the
processing head 1 and the recording head 2 moving horizontally in the conveyance direction
of the recording target P, the processing head 1 and the recording head 2 may move
horizontally in a direction orthogonal to the conveyance direction of the recording
target P.
[0053] That is, as long as the processing head 1 and the recording head 2 are provided,
the effect of using the processing solution of the present embodiment can be obtained
regardless of the type of inkjet recording device.
[Ink]
[0054] The ink used with the processing solution for inkjet recording of the present embodiment
is not particularly limited. For example, an ink containing a pigment and an aqueous
medium can be used. The ink may further contain at least one selected from the group
consisting of surfactants, polyols, and binder resin particles as required.
[0055] As a pigment, for example, a dispersible pigment dispersed in an aqueous medium can
be used. From the viewpoint of obtaining an ink excellent in image density, hue, and
color stability, the volume median diameter (D
50) of the pigment is preferably 30 nm or more and 250 nm or less, more preferably 70
nm or more and 160 nm or less. In the present specification, the measured volume median
diameter (D
50) is a median diameter measured using a laser diffraction/scattering particle size
distribution measuring apparatus ("LA-950", manufactured by HORIBA, Ltd.).
[0056] Examples of the pigment include yellow pigments, orange pigments, red pigments, blue
pigments, purple pigments, and black pigments. Examples of the yellow pigment include
C.I.Pigment Yellow (74, 93, 95, 109, 110, 120, 128, 138, 139, 151, 154, 155, 173,
180, 185, and 193). Examples of the orange pigment include C.I.Pigment Orange (34,
36, 43, 61, 63, and 71). Examples of the red pigment include C.I.Pigment Red (122
and 202). Examples of the blue pigment include C.I.Pigment Blue (15, more specifically
15:3). Examples of the purple pigment include C.I.Pigment Violet (19, 23, and 33).
Examples of the black pigment include C.I.Pigment Black (7).
[0057] The content of the pigment is preferably 1 weight % or more and 12 weight % or less,
more preferably 1 weight % or more and 7 weight % or less, with respect to the total
weight of the ink. The content of the pigment being 1 weight % or more improves the
image density of a recorded object to be formed. The content of the pigment being
12 weight % or less gives an ink having high fluidity.
[0058] In particular, the ink of the present embodiment preferably contains an anionic pigment.
Using such an ink, electric reactive aggregation of the cationic polymer and the anionic
pigment contained in the processing solution described above occurs on the surface
of the recording target, and this suppresses permeation of a binder resin (binder
resin described later) contained in the ink into the recording medium. When the recording
medium is a fabric, the chances of the binder resin penetrating into gaps between
fibers to bind the fibers to each other can be lowered. Accordingly, the fabric texture
(touch, etc.) of the textile printing target can be improved.
[0059] Specifically, as the anionic pigment, an anionic pigment having an anion group such
as a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic
acid group, a phenylsulfonic acid group, and a phenylcarboxyl group is more preferable.
[0060] The aqueous medium contained in the ink of the present embodiment is a medium containing
water as a main component. The aqueous medium may function as a solvent or as a dispersion
medium. Specific examples of the aqueous medium include water and a mixed solution
of water and a polar solvent. Examples of the polar solvent contained in the aqueous
medium include methanol, ethanol, isopropyl alcohol, butanol, and methyl ethyl ketone.
The content of water in the aqueous medium is preferably 90 weight % or more, preferably
in particular, 100 weight %. The content of the aqueous medium is preferably 5 weight
% or more and 70 weight % or less, more preferably 40 weight % or more and 60 weight
% or less, with respect to the total weight of the ink.
[0061] Furthermore, the surfactant contained in the ink improves the wettability of the
ink on the recording target. Examples of the surfactant include anionic surfactants,
cationic surfactants, nonionic surfactants, and amphoteric surfactants. The surfactant
contained in the ink is preferably a nonionic surfactant. The nonionic surfactant
is preferably a surfactant having an acetylene glycol structure, more preferably an
acetylene diol ethylene oxide adduct. The HLB value of the surfactant is preferably
3 or more and 20 or less, more preferably 6 or more and 16 or less, further more preferably
7 or more and 10 or less. The HLB value of the surfactant is calculated, for example,
by Griffin method using the formula "HLB value = 20 × (sum of formula weight of hydrophilic
portions)/molecular weight". To improve the image density while suppressing offset
of an image, the content of the surfactant is preferably 0.1 weight % or more and
5.0 weight % or less, more preferably 0.5 weight % or more and 2.0 weight % or less,
with respect to the total weight of the ink.
[0062] Furthermore, containing a polyol in ink suitably adjusts the viscosity of the ink.
A polyol contained in ink is preferably a diol or a triol. Examples of the diol include
glycol compounds, more specifically, ethylene glycol, propylene glycol, diethylene
glycol, triethylene glycol, and tetraethylene glycol. Examples of triol include glycerin.
[0063] To suitably adjust the viscosity of an ink containing a polyol, it is preferable
that the content of the polyol is 5 weight % or more and 60 weight % or less, more
preferably 20 weight % or more and 50 weight % or less, with respect to the total
weight of the ink.
[0064] The binder resin particles contained in the ink of the present embodiment are dispersed
in the aqueous medium. The binder resin particles function as a binder that bonds
the textile printing target and the pigment to each other. Thus, with the binder resin
particles contained in the ink, a textile printing article having excellent pigment
fixability can be obtained.
[0065] Examples of the resin contained in the binder resin particles include urethane resin,
(meth)acrylic resin, styrene-(meth)acrylic resin, styrene-maleic acid copolymer, vinyl
naphthalene-(meth)acrylic acid copolymer, and vinyl naphthalene-maleic acid copolymer.
The resin contained in the binder resin particles is preferably a urethane resin.
The content of the urethane resin in the binder resin particles is preferably 80 weight
% or more, more preferably 100 weight %.
[0066] The content of the binder resin is preferably 1 weight % or more and 20 weight %
or less, more preferably 2 weight % or more and 10 weight % or less, with respect
to the total weight of the ink. When the content of the binder resin particles is
1 weight % or more, a recording target with excellent pigment fixability can be obtained.
Meanwhile, when the content of the binder resin particles is 20 weight % or less,
the ink can be stably discharged to the recording target.
[0067] Furthermore, the ink of the present embodiment may further contain a known additive
(more specifically, for example, a dissolution stabilizer, a desiccation inhibitor,
an antioxidant, a viscosity modifier, a pH modifier, or an antifungal agent) as necessary.
[0068] The ink used in the present embodiment is produced, for example, by mixing a pigment,
an aqueous medium, and a component added as necessary (for example, a surfactant,
a polyol, and binder resin particles) using a stirrer. The mixing time is, for example,
1 minute or more and 30 minutes or less.
[Ink set]
[0069] The present embodiment also includes an ink set including the inkjet processing solution
described above and an inkjet ink.
[0070] The inkjet ink is preferably an ink containing an anionic pigment, further preferably
an ink containing an anionic pigment and a binder resin.
[0071] In particular, the ink set of the present embodiment is preferably a textile printing
ink set that exhibits, when used for textile printing, an excellent effect of improving
the texture of a textile printing target
[Textile printing method]
[0072] The present embodiment also includes a textile printing method using the inkjet processing
solution described above and an inkjet ink.
[0073] When using a pigment ink with which printing can be performed on many kinds of cloths,
it is necessary to fix the pigment to a surface of fabric. Failing to fix the pigment
to the surface of fabric results in poor fastness to rubbing. Meanwhile, the pigment
and the binder resin not staying on the surface of fabric and deeply penetrating into
the fabric result in poor chromogenic property, and moreover the ink and the binder
resin that are entered between fibers disadvantageously cause hard touch, that is,
degradation of texture.
[0074] According to the textile printing method of the present embodiment, the above-described
problem can be addressed to be solved by using the processing solution described above.
[0075] Specifically, the problem can be solved by substantially the same method as the recording
method described in the "Inkjet recording method using processing solution", except
that the recording target is changed to a textile printing target. Examples of the
textile printing target include all kinds of cloths. Specifically, the cloth may be
a woven fabric a knitted fabric, or a nonwoven fabric. The examples include cotton
fabric, silk fabric, hemp fabric, acetate fabric, rayon fabric, nylon fabric, polyurethane
fabric, and polyester fabric.
[0076] As the inkjet ink for textile printing, among inks described above, an ink containing
an anionic pigment is preferably used, more preferably an ink containing an anionic
pigment and a binder resin is used.
[0077] According to the textile printing method of the present embodiment, excellent chromogenic
property can be obtained while suppressing corrosion of an inkjet head member and
yellowing of a textile printing target, and moreover, degrading of the texture of
a fabric that is a textile printing target can be suppressed. Thus, the method is
very useful in industrial use.
[0078] In the present embodiment, the processing solution does not require a work such as
padding and drying the fabric in advance, and can be applied to the fabric by an inkjet
system. This advantageously and greatly reduces the work of adjusting the fabric.
Examples
[0079] The present disclosure will be described more specifically below with reference to
examples, though the present disclosure is by no means limited by the examples.
(Example 1)
• Adjustment of cationic polymer
[0080] The column was filled with 0.5 L of a strongly basic ion exchange resin (OH type),
and 1 L of "PAS-A5" (manufactured by Nittobo Medical Co., Ltd.) was passed through
the column at a flow rate of 50 ml/min to obtain an adjusted cationic polymer solution
1. PAS-A5 is a cationic polymer of a quaternary ammonium salt (diallyldimethylammonium
chloride-sulfur dioxide copolymer). The solid content of the obtained adjusted cationic
polymer solution 1 was 40%.
• Preparation of processing solution
[0081] 3 parts by weight (solid content) of the obtained adjusted cationic polymer solution
1, 2 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 1 (pH 8.5, chloride ion concentration 4.6 g/L).
(Example 2)
• Adjustment of cationic polymer
[0082] The adjusted cationic polymer solution 1 obtained in Example 1 was once again passed
through the column at a flow rate of 50 ml/min to obtain an adjusted cationic polymer
solution 2. The solid content of the obtained adjusted cationic polymer solution 2
was 40%.
• Preparation of processing solution
[0083] 3 parts by weight (solid content) of the obtained adjusted cationic polymer solution
2, 2 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 2 (pH 9.0, chloride ion concentration 0.5 g/L).
(Example 3)
[0084] By the same manner as in Example 1 except that the amount of the adjusted cationic
polymer solution 1 of Example 1 was changed from 3 parts by weight to 0.5 parts by
weight, a processing solution 3 was obtained (pH 7.8, chloride ion concentration 1.1
g/L).
(Example 4)
[0085] By the same manner as in Example 2 except that the amounts of the adjusted cationic
polymer solution 2 and the lactic acid of Example 2 were changed from 3 parts by weight
to 30 parts by weight and from 2 parts by weight to 18 parts by weight, respectively,
and the amount of the propylene glycol was changed to 5 parts by weight, a processing
solution 4 was obtained (pH 9.0, chloride ion concentration 5.0 g/L).
(Example 5)
• Adjustment of cationic polymer
[0086] The column was filled with 0.5 L of a strongly basic ion exchange resin (OH type),
and 1 L of "PAS-21" (manufactured by Nittobo Medical Co., Ltd.) was passed through
the column at a flow rate of 50 ml/min to obtain an adjusted cationic polymer solution
3. "PAS-21" is a cationic polymer of a secondary amine (diallylamine polymer). The
solid content of the obtained adjusted cationic polymer solution 3 was 15%.
• Preparation of processing solution
[0087] 3 parts by weight (solid content) of the obtained adjusted cationic polymer solution
3, 2 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 5 (pH 8.4, chloride ion concentration 3.1 g/L).
(Example 6)
• Adjustment of cationic polymer
[0088] The column was filled with 0.5 L of a strongly basic ion exchange resin (OH type),
and 1 L of "PAS-2201CL" (manufactured by Nittobo Medical Co., Ltd.) was passed through
the column at a flow rate of 50 ml/min to obtain an adjusted cationic polymer solution
4. "PAS-21" is a cationic polymer of a tertiary amine (methyldiallylamine hydrochloride-sulfur
dioxide copolymer). The solid content of the obtained adjusted cationic polymer solution
4 was 25%.
• Preparation of processing solution
[0089] 3 parts by weight (solid content) of the obtained adjusted cationic polymer solution
4, 2 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 6 (pH 8.2, chloride ion concentration 3.3 g/L).
(Example 7)
[0090] By the same manner as in Example 1 except that the amount of the adjusted cationic
polymer solution 1 of Example 1 was changed from 3 parts by weight (solid content)
to 0.4 parts by weight (solid content), a processing solution 7 was obtained (pH 7.3,
chloride ion concentration 1.0 g/L).
(Comparative Example 1)
[0091] 3 parts by weight (solid content) of "PAS-A5 " (manufactured by Nittobo Medical Co.,
Ltd.), 1% of sodium hydroxide of 1 N, 1 part by weight of nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 8 (pH 7.3, chloride ion concentration 5.6 g/L).
(Comparative Example 2)
[0092] 3 parts by weight (solid content) of the obtained adjusted cationic polymer solution
1, 0.5 parts by weight of lactic acid, 1 part by weight of a nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 9 (pH 10.0, chloride ion concentration 4.6 g/L).
(Comparative Example 3)
[0093] 3 parts by weight (solid content) of the adjusted cationic polymer solution 1, 1
part by weight of a nonionic surfactant "Surfynol 440" (manufactured by Nissin Chemical
Industry Co., Ltd.), 10 parts by weight of propylene glycol, and water as the balance
were mixed, and then filtered with a 5 µm filter to obtain a processing solution 10
(pH 10.9, chloride ion concentration 4.6 g/L).
(Comparative Example 5)
[0094] 3 parts by weight (solid content) of the adjusted cationic polymer solution 1, 0.8
parts by weight of acetic acid, 1 part by weight of a nonionic surfactant "Surfynol
440" (manufactured by Nissin Chemical Industry Co., Ltd.), 10 parts by weight of propylene
glycol, and water as the balance were mixed, and then filtered with a 5 µm filter
to obtain a processing solution 11. (pH 8.4, chloride ion concentration 4.6 g/L)
(Preparation of ink)
[0095] An ink was prepared using an anionic pigment dispersion "AE-2078F" (manufactured
by Sanyo Color Works, Ltd.) having a pigment concentration of 20%, a urethane dispersion
"SUPERFLEX 470" (manufactured by DKS Co., Ltd.) having a solid content of 38%, a nonionic
surfactant "Surfynol 440" (manufactured by Nissin Chemical Industry Co., Ltd.), propylene
glycol, and water.
[0096] Specifically, the composition of the ink was 4 weight % of the pigment, 8 weight
% of the urethane, 30 weight % of the propylene glycol, 1 weight % of the surfactant,
and water as the balance. By mixing at the above ratio and filtering with a 5 µm filter,
the ink was obtained.
(Preparation of post-processing solution)
[0097] A post-processing solution was prepared using a silicone oil emulsion "POLON-MF-51"
(manufactured by Shin-Etsu Chemical Co., Ltd.) having a silicone oil content of 39%,
propylene glycol, and water. Specifically, the composition was 10 weight % of silicone
oil, 30 weight % of propylene glycol, and water as the balance. By mixing at the above
ratio and filtering with a 5 µm filter, the post-processing solution was obtained.
< Printing >
[0098] For inkjet printing, a flatbed printing jig in which KJ4B heads manufactured by KYOCERA
Corporation were arranged in a conveyance direction was used. The preprocessing solution
was charged into the first head, the ink was charged into the second head, and the
post-processing solution was charged into the third head. Then, inkjet printing was
performed under the following condition. For only Comparative Example 4, printing
was performed without the preprocessing solution.
Cloth used: Polyester Tropical
Distance between cloth and head: 3 mm, Head temperature: 25°C
Drying: 150°C for 3 minutes (in oven)
[0099] < Evaluation test >
(Image density)
[0100] Color was measured using the fluorescence spectrophotometric colorimeter FD-5 (manufactured
by Konica Minolta, Inc.). The evaluation criteria were as follows. Image density (OD)
of 1.3 or more "excellent", very good chromogenic property Image density (OD) of 1.25
or more and less than 1.3 "good", good chromogenic property Image density (OD) of
less than 1.25 "poor ", poor chromogenic property
(Yellowing of fabric)
[0101] Using the fluorescence spectrophotometric colorimeter FD-5 (manufactured by Konica
Minolta, Inc.), the concentration of the fabric itself and the (yellow) concentration
of a portion to which the preprocessing solution is applied were measured, and the
difference between the two concentrations was defined as ΔOD. The evaluation criteria
were as follows. ΔOD of less than 0.05 "excellent", yellowing cannot be recognized
visually, very good ΔOD of 0.05 or more and less than 0.10 "good", slightly yellowed,
good ΔOD of 0.10 or more "poor", yellowed
(Texture)
[0102] An unused textile printing target was folded in two along a warp (the longitudinal
direction), and the distance between the lower fabric and the upper fabric (loop height)
at the fold line was measured. The measured loop height of the unused textile printing
target was defined as the loop height before textile printing. Next, the region in
which a solid image was formed of a textile printing article for evaluation was folded
in two along a warp (the longitudinal direction), and the loop height was measured.
The measured loop height of the textile printing article for evaluation was defined
as the loop height after textile printing. From the formula "loop height change rate
= 100 × (loop height after textile printing)/(loop height before textile printing)",
the loop height change rate (unit of %) between before and after textile printing
was calculated. A lower loop height change rate means that the textile printing target
has less hardened and less bulged by the textile printing, indicating that the degrading
of texture of the textile printing article was suppressed. The evaluation criteria
were as follows.
Less than 130% "good", Texture change is small, good.
130% or more "poor", Hard texture, poor.
(Corrosion of metal member)
[0103] About 0.1 g of a piece of SUS 430 was precisely weighed, immersed in a processing
solution that was weighed to be 50 g in a 50 ml glass bottle, and left at 60°C for
1 month with the glass bottle capped. After 1 month, the piece of SUS 430 was taken
out, washed with ion-exchanged water, dried, and weighed. The weight change rate was
obtained by the following formula.
The evaluation criteria were as follows.
Weight change rate (%) of 98% to 100% "good", No corrosion, very small weight change.
Weight change rate (%) of less than 98% "poor", Corrosion progressed, large weight
reduction.
[0104] The results of the above evaluation tests are summarized in Table 1.
[Table 1]
|
Cationic polymer |
Content (weight %) |
Acid |
Content (weight %) |
pH |
Halogen ion concentration (g/L) |
Image density |
Yellowing of fabric |
Texture |
Metal member |
Example 1 |
Quaternary ammonium salt |
3 |
Lactic Acid |
2 |
8.5 |
4.6 |
1.35 Excellent |
0.02 Excellent |
110 Good |
99.8 Good |
Example 2 |
Quaternary ammonium salt |
3 |
Lactic Acid |
2 |
9 |
0.5 |
1.34 Excellent |
0.03 Excellent |
109 Good |
99.5 Good |
Example 3 |
Quaternary ammonium salt |
0.5 |
Lactic Acid |
2 |
7.8 |
1.1 |
1.30 Excellent |
0 Excellent |
121 Good |
99.9 Good |
Example 4 |
Quaternary ammonium salt |
30 |
Lactic Acid |
18 |
9 |
5 |
1.45 Excellent |
0.09 Good |
105 Good |
99.8 Good |
Example 5 |
Secondary amine |
3 |
Lactic Acid |
2 |
8.4 |
3.1 |
1.28 Good |
0.03 Excellent |
112 Good |
99.0 Good |
Example 6 |
Tertiary amine |
3 |
Lactic Acid |
2 |
8.2 |
1 |
1.28 Good |
0.03 Excellent |
115 Good |
99.1 Good |
Example 7 |
Quaternary ammonium salt |
0.4 |
Lactic Acid |
2 |
7.3 |
1 |
1.25 Good |
0.02 Excellent |
128 Good |
99.9 Good |
Comparative Example 1 |
Quaternary ammonium salt |
3 |
- |
- |
7.3 |
5.6 |
1.36 Excellent |
0.08 Good |
110 Good |
91.0 Poor |
Comparative Example 2 |
Quaternary ammonium salt |
3 |
Lactic Acid |
0.5 |
10 |
4.6 |
1.35 Excellent |
0.15 Poor |
113 Good |
99.4 Good |
Comparative Example 3 |
Quaternary ammonium salt |
3 |
- |
- |
10.9 |
4.6 |
1.35 Excellent |
0.20 Poor |
114 Good |
99.4 Good |
Comparative Example 4 |
- |
- |
- |
- |
- |
- |
1.10 Poor |
0 Excellent |
149 Poor |
- |
Comparative Example 5 |
Quaternary ammonium salt |
3 |
Acetic Acid |
0.8 |
8.4 |
4.6 |
1.33 Excellent |
0.25 Poor |
111Good |
98.9 Good |
(Discussion)
[0105] From the results in Table 1, it was confirmed that corrosion of a metal member can
be suppressed by the processing solution of the present disclosure. Furthermore, it
was found that printing using the processing solution of the present disclosure is
excellent in chromogenic property (image density) and can suppress yellowing of fabric,
and by this printing, a printing article that is excellent in texture can be obtained.
In particular, it was found from comparison between Examples 1 to 3 and Example 4
that yellowing of fabric is further suppressed by setting the amounts of the cationic
polymer and the lactic acid within suitable ranges. Furthermore, it was found from
comparison between Examples 1 to 3 and Examples 5 to 7 that use of the quaternary
ammonium-containing cationic polymer at a suitable content exhibits a further excellent
image density.
[0106] Meanwhile, in Comparative Example 1 in which the processing solution containing no
lactic acid and having a halogen ion (chloride ion) concentration exceeding 5 g/L
was used, corrosion of the metal member occurred. In Comparative Example 2 in which
the processing solution having a pH exceeding 9 was used, and in Comparative Example
3 in which the processing solution having a pH exceeding 9 and containing no lactic
acid was used, yellowing of fabric occurred. In Comparative Example 4 in which no
preprocessing solution was used, the image density decreased and texture was poor.
Furthermore, in Comparative Example 5 in which the processing solution using acetic
acid instead of lactic acid was used, yellowing occurred.
Reference Signs
[0107]
- 1
- processing head
- 2
- recording head
- 2a
- first recording head
- 2b
- second recording head
- 2c
- third recording head
- 2d
- fourth recording head
- 3
- mounting table
- 10
- Inkjet recording device
- P
- recording target